Pharmacokinetics, tissue distribution and metabolism study of 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside in a rat model of ischemic stroke using UHPLC‑Q‑TOF-MS/MS.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (TSG), is a unique active ingredient isolated from Polygonum multiflorum Thunb., which has been reported excellent anti-ischemic stroke activities. However, TSG's low lipophilicity seems to limit its ability to cross the BBB, raising concerns about its pharmacokinetics, tissue distribution and metabolism. Here, we compared the pharmacokinetics, tissue distribution, and metabolism of TSG (10 mg/kg, i.v.) in healthy and a middle cerebral artery occlusion (MCAO) model rats with the UHPLC-Q-TOF MS/MS, to evaluate its potential and rationality for treating ischemic stroke. Distinctive adducts and novel metabolites were identified in vivo and effectively distinguished by molecular networking analysis. Notably, the metabolites M1&3 were generated from TSG via riboside and glucoside conjugation reactions, processes that have not been reported in mammalian drug metabolism. Pharmacokinetic analysis demonstrated that non-significant differences were observed in the Cmax, AUC(0-t/∞), Vd, t1/2, CL values, plasma and tissue (heart, liver, spleen, lung, kidney and testis) levels between MCAO and sham rats except for brain penetration. TSG and its mono-glucuronidate conjugate (metabolite M2) exposure in ischemic left cerebral area of MCAO rats was found significant higher compared to Sham rats. While, the systemic levels of metabolites M1∼3 in MCAO rats were observed lower than those in Sham, especially in liver, kidney and spleen, indicating that MCAO would weaken TSG metabolism and interfere its clearances. This study provided a theoretical reference for further clarification of TSG pharmacodynamic basis to be a potential neuroprotectant candidate.